The electric power distribution system is the link between the terminal users and power generation/transmission system, and is also the important part for guaranteeing the reliable power supply for the users. Smart Grid will completely change the electric power distribution system and realize sufficient information technology. It can obtain a great deal of real-time information from power distribution network via new sensors and means of communication. The smart switch apparatus will be widely used, thus providing a brand-new foundation for secure and efficient operation of the electric power distribution system. In recent decades, in electric power transmission system, the research in security region has led to a series of achievements which have been applied in National Electric Power Dispatching and Communication Center, provincial dispatching center, such as Tianjin city and Henan Province in China, and in North America. With ever-increasing the understanding to property and regularity of power system security boundaries, the method of security region provides relative position of the system operating point in the security region, and thus various necessary information can be obtained. The method reduces calculation and simplifies the handling of stability constraints in optimization problems which associated with dispatching. The security theoretical research of electric power distribution system is pretty weak compared to power transmission system. The “Urban Power Network Planning and Design Guidelines” defines N−1 security rule, and develops regulating, constructing and operating the power grid based on the rule.
In fulfilling this invention, the inventor found that the prior art bears the following defects and shortcomings.
The prior art security researches regarding electric power distribution system are presently restricted to N−1 method and power restoration after power breakdown. The N−1 security analytical method of traditional electric power distribution system is to hypothesize fault to each element and analyze security after fault, which has the disadvantages as huge calculation, and slow speed. Moreover, the traditional method is adapted to analysis at off-line, which cannot satisfy the requirements of real-time and on-line operation.